Free flowing soap-nonionic detergent

ABSTRACT

NOVEL PARTICULATE BLENDS OF SOAP AND LIQUID NONIONIC SURFACTANTS AND A METHOD FOR PREPARING SAME, IS DISCLOSED. THE NEW METHOD INCLUDES THE COMBINATION OF AN APPROPPRIATE FATTY ACID WITH THE LIQUID NONIONIC SURFACTANT BEFORE SAPONIFICATION OF THE AICD. THE NOVEL PARTICULATE BLENDS ARE DRY, NON-TACKY AND FREE FLOWING AND ARE SUITABLE FOR POST ADDITION TO SPRAY DRIED DETERGENT POWDERS OR FOR USE BY THEMSELVES OR WITH BUILDERS AS FINAL DETERGENT FORMULATIONS.

United States Patent 3,814,692 FREE FLOWING SOAP-NONIONIC DETERGENT John H. Mostow, Metuchen, N.J., assignor to Colgate- Palmolive Company, New York, NY.

No Drawing. Continuation of abandoned application Ser. No. 167,452, July 29, 1971. This application July 9, 1973, Ser. No. 377,678

Int. Cl. Clld 9/26 US. Cl. 252-108 7 Claims ABSTRACT OF THE DISCLOSURE Novel particulate blends of soap and liquid nonionic surfactants and a method for preparing same, is disclosed. The new method includes the combination of an appropriate fatty acid with the liquid nonionic surfactant before saponification of the acid. The novel particulate blends are dry, non-tacky and free flowing and are suitable for post addition to spray dried detergent powders or for use by themselves or with builders as final detergent-formulations.

This is a continuation of application Ser. No. 167,452, filed July 29, 1971, now abandoned.

The present invention relates to heavy duty, particulate, detergent formulations. Specifically the invention provides a method for incorporating relatively large amounts, typically above about percent by weight, of liquid nonionic surfactants into heavy duty particulate detergent formulations. More specifically, a method for combining liquid nonionic surfactants with soap, in free flowing particulate form, is provided by the invention. The new soap-nonionic particulate material has approximately the same density as spray dried detergent powders and can be utilized, in combination with builders, as a final detergent formulation, or it can be very advantageously post added to spray dried detergent formulations.

The most commonly used surface active agents in heavy duty detergent formulations are anionic compounds having detersive properties. Typical of these anionic compounds are the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates. These synthetic detergents are very effective in removing dirt from textile fabrics when utilized in conjunction with phosphate builders which function to soften the water being used and to provide detersive action. However, considerable controversy exists today as to the eflicacy of utilizing phosphate compounds in detergent formulations due to their alleged causation of the eutrophication process in lakes, rivers, and streams. Although the eutrophication process, wherein an excessive growth of aquatic plant life is promulgated in natural water bodies, is not completely understood, it is alleged that the phosphate compounds present in detergent containing waste water are a prime factor in promoting this phenomenon.

It has been discovered that when the phosphate content of a detergent formulation is substantially reduced, the nonionic surfactants appear to provide detergent properties that are superior to anionics in the same reduced phosphate content formulation. Apparently the detersive effectiveness of nonionic surfactants is effected much less by water hardness than that of the commonly used anionic surfactants. In the event that the phosphate builders are totally or partially removed from detergents, the incorporation of progressively larger amounts of nonioic surfactants into detergent formulations either in place of or in addition to anionic surfactants may become very desirable.

At present, small amounts of nonionic surfactants are added to detergent formulations, primarily to reduce the amount of foam generated during the washing cycle. However, it has been found that when a substantial ice amount, typically above 5% by weight, of nonionic surfactants is incorporated into the detergent slurry before spray drying, a pluming problem, manifested by a dense black smoke being discharged from the spray tower, may be encountered.

The combination of soap with a liquid nonionic surfactant in a detergent formulation is particularly advantageous since it results in a reduction or elimination of the high sudsing that is characteristic of anionic surfactants in detergent formulations. Prior art attempts to combine soap with liquid nonionic surfactants has typically resulted in a gel like mass that ultimately separates into two phases, and is unsuited for use in combination with powdered detergents. The primary advantage of the present invention is a method for combining liquid nonionic surfactants with soap in a dry, free flowing particulate form that may be readily utilized in combination with builders as a final detergent formulation or post added to spray dried detergent formulations to significantly increase the nonionic surfactant content of the final detergent product.

The nonionic surfactant component of the invention is well known and may be defined as the reaction product of ethylene oxide with a hydrophobic compound containing a carboxyl mercapto, amido, amino or hydroxy group. A preferred type of nonionic surfactant for use in accordance with the invention are ethoxylated long carbon chain alcohols. Typically, nonionic ethoxamers of this type have an 8 to 20 carbon atom alkyl chain preferably 14 to 18 and an average of about 4 to 19 preferably 10 to 15 ethylene oxide units per molecule. The range of ethylene oxide content that provides the greatest detergency in these surfactants usually results in a material that is a viscous liquid at room temperature and therefore unsuitable for direct addition to spray dried detergent powder.

The fatty acid component of the new particulate blends includes naturally occurring saturated fatty acids as well as commercially produced fatty acids derived by hydrogenating natural products such as coconut oil, palm kernel oil, babasu oil etc. The fatty acids of the invention are characterized by having a C to C carbon chain. Preferably the C to C saturated fatty acids derived from beef and pork fat glycerides, and from palm, coconut and related oils are used. These acids are commonly known in the art as lauric (C myristic (C palmitic (C and stearic (C acids. Of course, equivalent synthetic fatty acids and mixtures of fatty acids can also be used in accordance with the invention.

Accordingly, the invention provides a method for forming particulate blends of soap and liquid nonionic surfactants that are free flowing, non-tacky and contain from about 10 to about 50, preferably about 25 percent non-' ionic by weight. In accordance with the invention, the new method includes the intimate mixing of the fatty acid from which the soap is derived with the nonionic surfactant prior to saponification of the acid with a neutralizing agent to produce the soap. In formulating the new free flowing blends, the fatty acid material is initially mixed with liquid nonionic material at an elevated temperature, usually between about F. and 200 F., until the two components become mutually soluble and form a relatively clear liquid. The clear solution is then neutralized by mixing with an alkali metal preferably sodium and potassium carbonate. The neutralized reaction mass is then permitted to cool to room temperature during which it puffs into a porous solid that can be mechanically broken up into a free flowing, non-tacky powder having a density approximately equivalent to that of spray dried detergent powders, typically between about 0.25 and 0.75 grams per cc., usually 0.34 grams per cc.

In accordance with a further specific aspect of the invention, the new method permits the production of a free flowing soap-liquid nonionic surfactant particulate blend having a nonionic content of up to about 50 percent by weight. The relatively high ethoxamer content of the new particulate blend permits a substantial increase in the nonionic surfactant content of powdered detergents while avoiding the handling, pluming and tackiness characteristics of prior art methods. For example, the post addition of the soap-nonionic surfactant material of the invention to a conventional powdered detergent to form a 50-50 percent by weight mixture results in a final prod uct having a nonionic surfactant content of up to about 25 percent by Weight.

The following specific examples are further illustrative of the nature of the present invention but it is understood that the invention is not limited thereto. All amounts and proportions are by weight unless otherwise indicated.

EXAMPLE 1 50 parts of a liquid ethoxylated fatty alcohol, having a 14- to 15 carbon atom alkyl chain and an average of 11 ethylene oxide units per molecule are mixed with 50 parts of lauric acid and heated to 180 -F. to form a clear solution. 100 parts of anhydrous sodium carbonate are mixed into the fatty acid-nonionic solution and the mixture is reheated to 180 F. and stirred until the neutralization reaction is complete. The mixing is then stopped and the reaction product is allowed to cool. During cooling the reaction product puffs to a porous solid that can be milled to particulate form. The resulting particulate material is dry, non-tacky and has a density of about 0.35 g./cc.

EXAMPLE 2 Example 1 is repeated with similar results using liquid nonionic surfactants derived by ethoxylating fatty alcohols having the following alkyl carbon atom chains and the indicated average number of ethylene oxide units per molecule.

Average number of Carbon atom chain: ethylene oxide units All of the foregoing soap-nonionic particulate blends are dry, free flowing and very suitable for post-addition to typical spray dried detergent powders.

EXAMPLE 3 Example 3 is repeated, with similar results, using each of the nonionic surfactants listed in example 2.

EXAMPLE 5 Example 3 is repeated, with similar results, using stearic acid in place of myristic acid.

EXAMPLE 6 Example 5 is repeated, with similar results using each of the nonionic surfactants listed in example 2- 4 EXAMPLE 7 Example 3 is repeated, with similar results using palmitic acid in place of myristic acid.

EXAMPLE 8 Example 7 is repeated, with similar results, using each of the nonionic surfactants listed in example 2.

EXAMPLE 9 50 parts of a liquid ethoxylated fatty alcohol having a 14 to 15 carbon atom alkyl chain and an average of 11 ethylene oxide units per molecule are mixed with 50 parts of a fatty acid mixture derived by combining 30 percent by weight hydrogenated coconut oil fatty acids and 70 percent by weight of hydrogenated tallow fatty acids. The fatty acid mixture has the following composi tion:

Percent C caprylic acid 2.5-3 C capric acid 2.0-3 C lauric acid 4.5-10 C myristic acid 8.0-l0 C palmitic acid 12.0-15 C stearic acid 71.0-59

Example 9 is repeated with similar results using a liquid nonionic ethoxamer having an alkyl chain of 16-18 carbon atoms and an average of 12 ethylene oxide units per molecule. A fatty acid mixture having the following composition is used.

Percent C lauric acid 10-15 C myristic acid 20-40 C palmitic acid 15-20 C stearic acid 55-25 C arachidic acid 8.0 C behenic acid 5.0

EXAMPLE 1 1 Example 9 is repeated with similar results using a mixture of fatty aclds having the following composition:

Percent C caprylic acid 5.0 C capric acid 6.0

C lauric acid 34.0 C myristic acid 15.0 C palmitic acid 14.0

Since the new soap-nonionic particulate blends are dry, non-tacky and free flowing and have about the same density as spray dried detergent powders, they are very suitable for use either in place of, or in combination with, typical spray dried powders by post adding the new soapnonionic blend to the detergent after spray drying. The new soap-nonionic particulate blend can also be utilized as a final detergent formulation either with or without builders, as desired. Although the foregoing specific examples are presently preferred in the practice of the invention, variations may be made and equivalents may be substituted without departing from the spirit of the invention. Consequently, reference should be made to the following claims in determining the full scope of the invention.

I claim:

1. A free flowing particulate detergent material consisting essentially of,

(a) from about up to about 50 percent by Weight, of a liquid nonionic surfactant chosen from the group consisting of ethoxylated fatty alcohols having an alkyl chain of from 8 to 20 carbon atoms and an average of from about 4 to about 19 ethylene oxide units per molecule,

(b) at least 50 percent by weight of soap an alkali metal chosen from the group consisting of the sodium and potassium salts of saturated C to C fatty acids,

(0) said nonionic surfactant and said soap being physically combined to form a free flowing, porous particulate material and (d) said free flowing porous particulate material having a density from 0.25 to 0.75 grams per cc.

2. The free flowing particulate detergent material of claim 1 further characterized by having a density of about 0.34 grams per cc.

3. The free flowing particulate detergent material of claim 1 further including an amount of water not greater than the Water generated during saponification of said soap.

4. The particulate detergent of claim 1 wherein,

(a) said ethoxylated fatty alcohol is chosen from the group having a alkyl chain of from about 14 to about 18 carbon atoms and an average of about 10 to about 12 ethylene oxide units per molecule.

5. The particulate detergent of claim 1 wherein,

(a) said alkali metal is sodium.

6. The particulate detergent of claim 1 wherein,

(a) said alkali metal is sodium and,

(b) said fatty acid is lauric acid.

7. The particulate deteregnt material of claim 1 where- (a) the amount of said nonionic surfactant is about 25 percent by weight.

References Cited UNITED STATES PATENTS 2,947,701 8/1960 'Ruif 252-109 2,875,153 2/1959 Dalton 252-132 2,774,735 12/1956 Becher 252--l17 2,595,300 5/1952 Safrin et a1 252-109 2,543,744 3/1951 Fox 252-132 FOREIGN PATENTS 903,781 8/1962 Great Britain 252-117 750,495 6/ 1956 Great Britain 252117 733,416 7/1955 Great Britain 252-432 OTHER REFERENCES Considerations in The Use of Nonionic Surface-Active Agents by C. E. Colwell & W. E. Rixon, Reprint From American Dyestufi Reporter, vol. 50, N0. 18, pages 39-42, September 1961.

Improvement of Soap with Ethylene Oxide Condensation Products by H. E. Tschakert, Manufacturing Chemist, 29, June 1958, pp. 233-236.

LELAND A. SEBASTIAN, Primary Examiner U.S. Cl. X.R.

25289, 109, 117, Dig. 1 

